Apparatus for preventing device deployment failure

ABSTRACT

An apparatus for preventing deployment failure or damage of a movable portion of a treatment device via a force limiting element in the treatment device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional Pat.Application No. 17/178,679, filed Feb. 18, 2021, which claims thebenefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Pat.Application No. 62/979,903, filed on Feb. 21, 2020, entitled “ApparatusFor Preventing Device Deployment Failure,” each of which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to medical devices, and moreparticularly to apparatuses for preventing deployment failure of amovable portion of a treatment device, where the movable portion isinvolved in manipulating tissue or anatomical structures within the bodyof a human or animal subject for the purpose of treating diseases ordisorders.

Various diseases or disorders of soft tissue and anatomical organs suchas the uterus, intestine, and prostate can require surgical interventionwith a treatment device to manipulate or remove abnormal, diseased,enlarged, or overgrown tissue. When such procedures are performed, thephysician or surgeon may encounter non-target tissue, such as bone,calcifications, or other hard or solid anatomical structures, duringintroduction or manipulation of the treatment device at theinterventional site of a patient, particularly when the interventionalsite is in close proximity to a soft-hard tissue interface.

One such interventional site that includes a soft-hard tissue interfaceis the anatomical region defined by the prostatic urethra, prostate, andpelvic bone commonly accessed during prostate resection procedures forthe treatment of urological diseases or disorders such as BenignProstatic Hyperplasia (BPH). BPH is one of the most common medicalconditions that affect men, especially elderly men. It has been reportedthat, in the United States, more than half of all men havehistopathologic evidence of BPH by age 60 and, by age 85, approximately9 out of 10 men suffer from the condition. Moreover, the incidence andprevalence of BPH are expected to increase as the average age of thepopulation in developed countries increases.

The prostate gland enlarges throughout a man’s life. In some men, theprostatic capsule around the prostate gland may prevent the prostategland from enlarging further. This causes the inner region of theprostate gland to squeeze the urethra. This pressure on the urethraincreases resistance to urine flow through the region of the urethraenclosed by the prostate. Thus, the urinary bladder has to exert morepressure to force urine through the increased resistance of the urethra.Chronic over-exertion causes the muscular walls of the urinary bladderto remodel and become stiffer. This combination of increased urethralresistance to urine flow and stiffness and hypertrophy of urinarybladder walls leads to a variety of lower urinary tract symptoms (LUTS)that may severely reduce the patient’s quality of life. These symptomsinclude weak or intermittent urine flow while urinating, straining whenurinating, hesitation before urine flow starts, feeling that the bladderhas not emptied completely even after urination, dribbling at the end ofurination or leakage afterward, increased frequency of urinationparticularly at night, and an urgent need to urinate.

In addition to patients with BPH, LUTS may also be present in patientswith prostate cancer, prostate infections, and chronic use of certainmedications (e.g. ephedrine, pseudoephedrine, phenylpropanolamine,antihistamines such as diphenhydramine, chlorpheniramine etc.) thatcause urinary retention especially in men with prostate enlargement.

Although BPH is rarely life threatening, it can lead to numerousclinical conditions including urinary retention, renal insufficiency,recurrent urinary tract infection, incontinence, hematuria, and bladderstones.

In developed countries, a large percentage of the patient populationundergoes treatment for BPH symptoms. It has been estimated that by theage of 80 years, approximately 25% of the male population of the UnitedStates will have undergone some form of BPH treatment. At present, theavailable treatment options for BPH include watchful waiting,medications (phytotherapy and prescription medications), surgery, andminimally invasive procedures.

For patients who choose the watchful waiting option, no immediatetreatment is provided to the patient, but the patient undergoes regularexams to monitor progression of the disease. This is usually done onpatients that have minimal symptoms that are not especially bothersome.

Surgical procedures for treating BPH symptoms include TransurethalResection of Prostate (TURP), Transurethral Electrovaporization ofProstate (TVP), Transurethral Incision of the Prostate (TUIP), LaserProstatectomy and Open Prostatectomy.

Minimally invasive procedures for treating BPH symptoms includeTransurethral Microwave Thermotherapy (TUMT), Transurethral NeedleAblation (TUNA), Interstitial Laser Coagulation (ILC), and ProstaticStents.

Many current methods of treating BPH carry a high risk of adverseeffects. These methods and devices either require general or spinalanesthesia or have potential adverse effects that dictate that theprocedures be performed in a surgical operating room, followed by ahospital stay for the patient. The methods of treating BPH that carry alower risk of adverse effects are also associated with a lower reductionin the symptom score. While several of these procedures can be conductedwith local analgesia in an office setting, the patient does notexperience immediate relief and in fact often experiences worse symptomsfor weeks after the procedure until the body begins to heal.Additionally, all device approaches require a urethral catheter placedin the bladder, in some cases for weeks. In some cases, catheterizationis indicated because the therapy actually causes obstruction during aperiod of time post operatively, and in other cases it is indicatedbecause of post-operative bleeding and potentially occlusive clotformation. While drug therapies are easy to administer, the results aresuboptimal, take significant time to take effect, and often entailundesired side effects.

New devices and methods have been developed for various procedures tolift, compress, support, reposition, ablate, or otherwise alterprostatic tissue in a discrete procedure or in combination with treatingBPH. Such devices and methods are disclosed in U.S. Pats. 7,645,286;7,758,594; 7,766,923; 7,905,889; 7,951,158; 8,007,503; 8,157,815;8,216,254; 8,333,776; 8,343,187; 8,394,110; 8,425,535; 8,663,243;8,715,239; 8,715,298; 8,900,252; 8,936,609; 8,939,996; 9,320,511;9,549,739; 10,105,132; and 10,299,780 which are hereby incorporated byreference herein in their entireties. During some procedures, a movableportion of the treatment device can strike bone, calcifications, orother solid or hard anatomical structures, causing damage, such asbreakage, bowing, or buckling, to the movable portion or other parts ofthe device operatively connected to the movable portion. Such damage mayprevent proper treatment.

In addition to devices and methods to treat BPH, there are devices andmethods to treat other conditions in which a treatment device uses amovable portion to manipulating tissue or anatomical structures withinthe body of a human or animal subject for the purpose of treatingdiseases or disorders. Such methods and devices may also experiencescenarios in which the movable portion suffers damage, or the intendedtreatment is frustrated, by the movable portion, or other parts of thedevice operatively connected to the movable portion, contacting solid orhard anatomical structures.

There remains a need for development of new systems for preventingdamage to movable portions of treatment devices when such portions, orother parts of the device operatively connected to the movable portion,encounter non-target tissue or structures. The present disclosureaddresses these needs.

SUMMARY OF THE INVENTION

Embodiments of the present invention are directed towards an apparatusfor preventing damage to a treatment device for manipulating tissues andanatomical or other structures within the body of a human or animalsubject for the purpose of treating diseases or disorders.

Embodiments of the present invention include an apparatus for mitigatingdamage to a treatment device, where the apparatus includes a treatmenttool coupled to a movable assembly at a proximal portion of thetreatment tool and a force limiting element connected to the proximalportion of the treatment tool and connected to the movable assembly. Theforce limiting element allows movement of the proximal portion of thetreatment tool in a proximal direction with respect to the movableassembly while maintaining the coupling between the movable assembly andthe proximal portion of the treatment tool when forces experienced bythe treatment tool increase to a predetermined amount of force.

In some embodiments, the force limiting element comprises a spring, areversibly engageable connector, or both. In some embodiments, thepredetermined amount of force is the amount of force needed to extendthe spring. In some embodiments, the predetermined amount of force isthe amount of force disengage the reversibly engageable connector.

In some embodiments, the proximal portion of the treatment tool furthercomprises a friction element that conditionally prevents movement of theproximal portion of the treatment tool with respect to the movableassembly. In some embodiments, the force limiting element assists inmoving the proximal portion of the treatment tool in a distal directionwith respect to the movable assembly when forces experienced by thetreatment tool decrease below the predetermined amount of force.

In some embodiments, the treatment tool is a suture or a needle.

In some embodiments, the apparatus further comprises an indicator,wherein the indicator indicates when the treatment tool has beencompletely deployed. In some embodiments, the indicator comprises avisual, audible, or tactile indicator.

Other features and advantages of embodiments of the present inventionwill become apparent from the following description, taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, certain principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, isometric view of a handle of a system fortreating benign prostatic hyperplasia.

FIG. 2A is an isometric view of a cartridge of a system for treatingbenign prostatic hyperplasia.

FIG. 2B is an isometric, enlarged view of a cartridge housing assemblyof the cartridge of FIG. 2A.

FIG. 3A is an isometric view of a force limiting assembly according toan embodiment of the invention.

FIG. 3B is an isometric view of a force limiting assembly according toan embodiment of the invention.

FIG. 4 is an isometric view of a portion of a force limiting assemblyaccording to an embodiment of the invention.

FIG. 5A is a top view of a force limiting assembly according to anotherembodiment of the invention.

FIG. 5B is a top view of a force limiting assembly according to anotherembodiment of the invention.

FIG. 6 is an isometric view of a force limiting connector according toanother embodiment of the invention.

FIG. 7 is an isometric view of handle and cartridge system having adeployment indicator according to another embodiment of the invention.

FIG. 8 is a side view of a section of a handle having a deploymentindicator according to another embodiment of the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Numerous specific details are set forth herein to provide a thoroughunderstanding of the claimed subject matter. However, those skilled inthe art will understand that the claimed subject matter may be practicedwithout these specific details. In other instances, methods,apparatuses, or systems that would be known by one of ordinary skillhave not been described in detail so as not to obscure claimed subjectmatter.

The use of “adapted to” or “configured to” herein is meant as open andinclusive language that does not foreclose devices adapted to orconfigured to perform additional tasks or steps. The use of “proximal”and “distal” herein refers to relative positions with respect to a userof the elongate, minimally invasive devices, where “proximal” meansrelatively towards the user and “distal” means relatively away from theuser. Headings, lists, and numbering included herein are for ease ofexplanation only and are not meant to be limiting.

Generally, embodiments of the apparatus of the present disclosureprevent damage to a treatment device. Treatment devices delivered to theinterventional site of a patient can be equipped with various toolswhich manipulate, ablate, or otherwise alter tissue. Such tools caninclude, but are not limited to, needles, cutting blades, vacuums,grasping arm assemblies, expandable cutting members, blunt dissectors,noose or ligature clips, articulating heads with an integral orretractable blade, helical blades, electrodes for delivery ofradiofrequency energy, cutting wires or rings, electrocauterizingprobes, or staple or suture delivery heads. These tools can be advancedfrom a working channel, needle, or puncturing element at the distal endof an elongate member of the treatment device such that the tool isunsheathed from the elongate member. In some embodiments, the tool canbe attached to the distal end of the elongate member and does notrequire unsheathing.

Turning now to the figures, which are provided by way of example and notlimitation, embodiments of the present disclosure is directed to anapparatus for limiting and/or dampening forces applied to a movableportion of a treatment device. Certain embodiments of the presentdisclosure additionally or alternatively are directed to an apparatusfor accommodating relative changes in length between two movableportions of a treatment device as those movable portions move withrespect to each other. In many cases, embodiments of the presentdisclosure can prevent damage to movable portions of a treatment devicewhile the treatment device is being used for manipulating tissues andanatomical or other structures within the body of a human or animalsubject for the purpose of treating diseases or disorders. The disclosedapparatus can be implemented in various treatment devices employed forvarious medical purposes including, but not limited to, retracting,lifting, compressing, approximating, supporting, remodeling,repositioning, ablating, or otherwise altering tissues, organs,anatomical structures, grafts, or other material found within the bodyof a human or animal subject. In certain embodiments, treatment devicesare intended to displace, compress, retract, or destroy tissue of theprostate to facilitate treatment of diseases or disorders such as BenignProstatic Hyperplasia (BPH).

Referring now to FIG. 1 , a BPH treatment device handle 100 is shown inan exploded, isometric view. The BPH treatment device handle 100includes a right handle case 101, a left handle case 102, and acartridge bay 103 formed in left handle case 102. The treatment devicehandle 100 is designed to transmit the energy stored in several springswithin the treatment device handle 100 to a cartridge (shown in FIG. 2A)to enable the treatment of BPH in a patient.

The treatment device handle 100 includes a handle trigger assembly 110,which is operatively connected to a handle trigger spring 111 such thatthe handle trigger spring 111 provides force sufficient to return thehandle trigger assembly to its initial position after the handle triggerassembly 110 has been squeezed and released by a user. A ratchet 114,which is connected to a ratchet spring 115, affects the motion of thehandle trigger assembly 110 such that the handle trigger assembly 110does not return to its initial position prior to being squeezed to apredetermined amount by a user. A safety 112 is connected to the handletrigger assembly 110 to ensure that the handle trigger assembly 110 isnot operated accidentally. The handle trigger assembly 110 is connectedto a drive gear 113, which is connected to a cam wheel 120.

The cam wheel 120 rotates about a central axis and, via structures andfeatures on the cam wheel, triggers certain motions within the treatmentdevice handle 100 as the cam wheel 120 rotates. There are multiple sledsoperatively connected to the cam wheel 120, and the sled move in alinear direction along a lateral axis of the treatment device handle100. There are multiple springs that impart force to the multiple sledsto general the motion and provide the mechanical energy sufficient todelivery an implant to treat BPH. A cartridge (depicted in FIG. 2A)includes multiple tab assemblies that mate with the sleds via slots inthe sled such that the motion and energy imparted by the operation ofthe mechanisms in the handle (such as the springs) is transmitted to themechanisms in the cartridge.

Specifically, an implant trigger 121 is operatively connected to the camwheel 120 and an implant sled 160, which is connected to an implantspring 161 that provides energy related to the delivery of the implant.A needle sled 140 is operatively connected to the cam wheel 120, and aneedle sled spring 141 provides energy related to the delivery of theimplant. A suture sled 150 is operatively connected to the cam wheel120, and a suture sled spring 151 provides energy related to thedelivery of the implant. In each of these cases, a sled may move atsufficient velocity such that if a portion of the system connected tothe sled encounters non-target hard tissue or other hard obstacles,damage to the device may result.

The treatment device handle 100 includes various other parts, such as acover plate 130, an endoscope tube 131, a scope lock 170, a sheath lock180, and various screws and/or fasteners to assemble the handle. Thecover plate 130 provides the interior base for the cartridge bay 103.The endoscope tube 131, the scope lock 170, and the sheath lock 180provide functionality for attaching an endoscope and other ancillaryequipment (such as a surgical sheath) to facilitate the procedure.

Referring now to FIG. 2A, which shows an isometric view, a cartridge 200is configured to couple with the treatment device handle 100. Acartridge housing 201 fits within the cartridge bay 103 of the treatmentdevice handle 100 and a cartridge elongate assembly 280 runs parallel tothe endoscope tube 131 of the treatment device handle 100. A distalportion 285 of the cartridge elongate assembly 280 includes exit portsfor a needle, which is configured to facilitate placement of an implant.Thus, the treatment device handle 100 and the cartridge 200 togetherform a system for placing an implant for treating BPH. The springs andsleds in the treatment device handle 100 transmit energy and movement totab assemblies in cartridge housing 201 to advance the needle intotissue and deploy the implant.

Area X of FIG. 2A is shown in an enlarged, isometric view in FIG. 2B.The cartridge housing 201 includes a needle tab assembly 240, a suturetab assembly 250, and an implant tab assembly 260. These tab assembliesinteract with the sleds and the springs in the treatment handle todeliver an implant for the treatment of BPH. Linear movement of thesetab assemblies translates into mechanical movements at and, in somecases, beyond the distal portion 285 of the cartridge elongate assembly280. For example, linear movement of the needle tab assembly 240 isrelated to movement of a penetrating needle from within the distalportion 285 of the cartridge elongate assembly 280 and into tissue, andfurther linear movement of the needle tab assembly 240 is related toretraction of the penetrating needle from tissue and back to within thedistal portion 285 of the cartridge elongate assembly 280. Similarly,linear movement of the suture tab assembly 250 is related to movement ofan implant from within the distal portion 285 of the cartridge elongateassembly 280 and into tissue, and further linear movement of the suturetab assembly 250 is related to deployment of the implant into tissue.And linear movement of the implant tab assembly 260 is related toassembly of the implant within tissue, including cutting a suture thatis part of the implant.

The implant is deployed in tissue via the relative movement of theneedle tab assembly 240 and the suture tab assembly 250. As a firststep, the needle tab assembly 240 and the suture tab assembly 250 movetogether at the same rate in a distal direction. That is, the needle tabassembly 240 and the suture tab assembly 250 maintain their relativepositions with respect to each other. Moving together, the needle tabassembly 240 and the suture tab assembly 250 advance a penetratingneedle and an implant to a position within the tissue of a patient. Theimplant is connected with a suture, and this suture is coupled to asuture tube that is connected with the suture tab assembly 250. It isimportant during this first step that the needle tab assembly 240 andthe suture tab assembly 250 maintain their relative positions withrespect to each other so that the implant maintains its position withinthe needle and so that the implant can be deployed from the needle. Theneedle and the implant within the needle advance from the distal portion285 of the cartridge elongate assembly 280.

As a second step, the needle tab assembly 240 moves proximally while thesuture tab assembly 250 is held at its distal position. This relativemovement of the needle tab assembly 240 with respect to the suture tabassembly 250 retracts the needle and deploys the implant. As a thirdstep, the suture tab assembly 250 is retracted to position the implantand to place tension on the suture connected with the implant. As athird step, the implant tab assembly 260 moves distally to attach aproximal piece to the suture to complete the implant and to cut thesuture, thereby fully deploying the implant.

The movement of the needle tab assembly 240, the suture tab assembly250, and the implant tab assembly 260 is accomplished through theinteraction of these tab assemblies with the springs and sleds in thetreatment device handle. The springs and sleds cooperate with the camwheel and other features of the treatment device handle to move the tabassemblies according to the steps disclosed herein.

The tab assemblies disclosed herein are connected with elements thatextend along all or part of the cartridge elongate assembly 280. Forexample, the needle tab assembly is connected to a needle and the suturetab assembly is connected to a suture, and the needle and the suture areconfigured such that at least a portion of the needle and at least aportion of the suture can extend through the distal portion 285 of thecartridge elongate assembly 280 and into tissue. The needle tab assemblymay or may not be directly connected to the needle and the suture tabassembly may or may not be directly connected to the suture. That is,there may be one or more intermediate structures that connect the partof the needle and/or the part of the suture that extend through thedistal portion 285 of the cartridge elongate assembly 280 and intotissue. For example, the suture may be connected to the suture tabassembly via a suture tube, which can be made of material that isrelatively more rigid than the suture to provide for the transmission ofa pushing force along the relatively more flexible suture. As anotherexample, the needle may be connected to the needle tab assembly via anover-molded section, which can be made of a less expensive material thanthe distal portion of the needle. Thus, the connections between the tabassemblies and the elements at the distal end of the cartridge elongateassembly can include tubes, over-molded sections, or equivalentintermediate portions.

In some embodiments, a fixed connection between the tab assemblies andthe other features of the cartridge and implant may lead to certainundesirable outcomes. In certain situations, the relative movement ofthe features of the cartridge and implant may be impeded, which canresult in an incomplete delivery of the implant. For example, the needlemay encounter non-target tissue, such as bone, as the needle advancesfrom the distal portion 285 of the cartridge elongate assembly 280. Inthis situation, the needle may bend or in some cases buckle as theneedle encounters bone. When the needle bends or buckles, the relativepositions between the end of the needle and the implant within theneedle can change due to the higher friction created in the bent orbuckled needle.

In normal implant delivery situations, the friction between the innersurface of the needle and the outer surface of the implant is balancedby the spring force transmitted from the suture sled spring through thesuture sled to the suture tab assembly. This balance of frictional forceand spring force keeps the implant and suture in the same positionrelative to the end of the needle. However, when the needle is bent orbuckled, the friction force can increase such that the friction forceexceeds the spring force. In this case, when the needle is retracted bythe needle tab assembly, this greater friction force prevents theimplant from being deployed out of the end of the needle. That is, thespring force is partially overcome by the friction force and the implantmoves proximally with the retracting needle and does not completelyemerge from the end of the needle. In other cases, the end of the needlemay become blocked and the implant cannot emerge from the distal end ofthe needle.

One possible consequence of the friction force exceeding the springforce is damage at or near the proximal end of the suture. For example,although the suture and connected implant move proximally with theretracting needle as described above, the proximal end of the suture isbeing held fixed by the suture tab assembly. Because the proximal end ofthe suture is being held fixed while the distal end of the suture ismoving proximally, the proximal end of the suture may buckle or beotherwise damaged. Such damage can prevent another attempt at deployingthe implant. That is, if the suture was not damaged, then the needlecould be retracted, the treatment device repositioned, and the needledeployed again in an attempt to avoid the non-target tissue that createdthe failed deployment. However, damage to the proximal end of the sutureat or near the suture tab assembly may prevent proper functioning of thesuture tab assembly during subsequent deployment attempts. Thus, it ishelpful to alter the connection between the suture and the suture tabassembly to accommodate a situation where the frictional force at thedistal end of the suture increases such that the suture and connectedimplant move proximally with the retracting needle. More generally, itis helpful to have a connection between the spring-loaded mechanicalelements of a system and the elements beings driven by thatspring-loaded force in the event that those driven elements encounterhigh friction or obstacles that prevent motion.

FIG. 3A and FIG. 3B are isometric views of a force limiting assemblyaccording to an embodiment of the invention. In this embodiment, theforce limiting assembly is configured to modify the suture tab assemblypresented herein. But the force limiting aspects of this force limitingassembly could be configured to modify the needle tab assembly, theimplant tab assembly, or other assemblies where force limiting aspectsare helpful for prevent damage to an element moved rapidly by a springforce or other force. In FIGS. 3A and 3B, a suture tab assembly 350includes a suture tab assembly connection block 352, which is aconnection area for a suture tube 351. A suture tube proximal endportion 355 couples with the suture tab assembly connection block 352and with a force limiting spring 356. As illustrated in FIG. 4 , thesuture tab assembly connection block 352 can include a suture tabconnection block passage 353. This suture tab connection block passage353 is present in FIGS. 3A and 3B and the suture tube proximal endportion 355 passes through the suture tab connection block passage 353as a way to couple the suture tube 351 to the suture tab assembly 350.While the suture tab connection block passage 353 is presented as a holein the suture tab assembly connection block 352, other similarconfigurations are within the scope of this disclosure. The suture tabconnection block passage 353 functions to couple the suture tube 351 tothe suture tab assembly 350 while still allowing the force limitingspring 356 to engage in certain situations. Other couplingconfigurations that allow the force limiting spring 356 to engage incertain situations while also coupling the suture tube 351 to the suturetab assembly 350 may be used.

The force limiting spring 356 is joined to the suture tube proximal endportion 355 and to the suture tab assembly 350. In FIG. 3A and FIG. 3B,the force limiting spring 356 is illustrated as joined to the suture tabassembly 350 at the suture tab assembly connection block 352. However,the force limiting spring 356 may be joined to any portion of the suturetab assembly 350 provided that the force limiting spring 356 isconfigured to provide the force limiting functions disclosed herein.Similarly, the force limiting spring 356 may be joined to the suturetube 351 at any location provided that the force limiting spring 356 isconfigured to provide the force limiting functions disclosed herein. Theforce limiting spring 356 is illustrated in FIG. 3A and FIG. 3B as acoil type spring, but other types of springs may be employed providedthat the spring is configured to function as a force limiting spring asdisclosed herein.

FIG. 3A and FIG. 3B illustrates that force limiting spring 356 is atension spring whose coils create a lumen through which the suture tube351 extends. The ends of such a tension spring can include a hook orloop such as, but not limited to, machine hooks, cross over centerhooks, side hooks, offset side hooks, V hooks, extended hooks,rectangular hooks, single or double twisted loop, open or closed loops,center loops, or side loops. In other embodiments, the force limitingspring 356 is a leaf spring or other spring mechanism. Indeed, thedescription of the force limiting spring 356 is meant to convey that theforce limiting spring 356 is a mechanism capable of accommodating theproximal movement of the suture tube and then assisting in returning thesuture tube to its initial position.

FIG. 3A illustrates the suture tab assembly 350 in a configuration wherethe force limiting spring 356 is in a relaxed position. In thisposition, the force limiting spring 356 is not engaged in limiting anyforces on the suture tube 351. FIG. 3B illustrates the suture tabassembly 350 in a configuration where the force limiting spring 356 isin an extended position. The force limiting spring 356 is being extendedby an increase in the frictional forces on the distal end of the suture.The increase in frictional forces could be due to the needle being bentor buckled, or by the distal end of the needle being blocked such thatthe implant and connected suture are not able to exit the needle as theneedle tab assembly is being retracted. That is, there is a conditionfather distal on the suture that has transmitted forces proximally tothe suture tab assembly 350. These transmitted forces are accommodatingthe force limiting spring 356 extending in a way that takes up thetransmitted forces. In this way, the relative positions of the implantand connected suture and the distal end of the needle are preserved in acircumstance where those positions would have otherwise changed due tothe increased friction and/or blockage at the distal portion of theneedle.

Thus, the spring force can be considered a predetermined force that thefriction force must overcome in order to engage the force limitingbehavior of the force limiting spring. The force limiting spring mayobeys Hooke’s law such that the spring force scales linearly with thelength of spring extension. The force limiting spring may also be aso-called “constant force” spring where for relatively small variationsaround an initial preloaded position the spring force is approximatelyconstant.

FIG. 5A and FIG. 5B are top views of a force limiting assembly accordingto another embodiment of the invention. In this embodiment, the suturetube 351 includes a friction element 358 near the area at which thesuture tube 351 is coupled with the suture tab assembly connection block352. In some embodiments, the friction element 358 is a collar orsimilar structure that conditionally prevents the suture tube 351 frommoving proximally through the suture tab assembly connection block 352and engaging the force limiting spring 356. In some embodiments thefriction element 352 is a flattened or crimped section of suture tube351 such that the cross section of the suture tube 351 at the frictionelement 352 is larger in at least one radial direction that the rest ofthe suture tube 351.

The conditional nature of the friction element 358 is such that aminimum force is required to push the friction element 358 through thesuture tab connection block passage 353. That is, the forces experiencedby the suture or suture tube as a result of the needle being bent orbuckled, or the distal end of the needle being blocked, must be greaterthan the force required to push the friction element 358 through thesuture tab connection block passage 353. Thus, there are embodimentswhere the resting force of the force limiting spring 356 is sufficientto balance the forces experienced by the suture and/or suture tube andin those embodiments a friction element is not needed. But there arealso embodiments where the use of a friction element is helpful ornecessary to balance the forces experienced by the suture and/or suturetube and prevent unwanted engagement of the friction limiting spring.

In this regard, the suture tab connection block passage 353 functions asa slip fit for the friction element 358. The width of the frictionelement 358 is configured selected to allow for the friction element 358to pass through the suture tab connection block passage 353 whensufficient force is applied to either the distal end of the suture tube(such as when the needle strikes bone or encounters other hard material)or the proximal end of the suture tube (such as when the force limitingspring 356 is returned to its initial position).The friction element 358can also be calibrated based on the location and physical properties ofnon-target tissue that may be encountered during use of the treatmentdevice at an interventional site of a patient.

Several of the embodiments disclosed herein rely on the force limitingspring to assist in returning the suture tube to its initial position.Proper deployment of an implant can then be attempted using the resethandle and cartridge system. There are also embodiments in which thereis a mechanism for accommodating the increased frictional force and/or ablockage at the distal end of the needle and then the suture tube ismanually returned to its initial position. In some embodiments, thesystem can be returned to an initial position via an actuator or triggeron the handle of the system.

In FIG. 6 , a suture tab assembly 450 includes a suture tab assemblyconnection block 452, which is a connection area for a suture tube 451.A suture tube proximal end portion 455 couples with the suture tabassembly connection block 452 and with a force limiting connector 456.The force limiting connector 456 includes a latch 458 that is configuredto reversibly engage with a notch 459. FIG. illustrates the case wherethe latch 458 is disengaged with the notch 459 as a result of the forceson the suture tube 451 increasing to the point that these forcesovercome the engagement force of the latch 458 with the notch 459. Thus,in this embodiment the engagement force between the latch 458 and thenotch 459 maintains the position of the suture tube 451 until the forceson the suture tube 451 have increased to the point that there is risk ofdamage to the suture and/or suture tube. After the latch 458 has becomedisengaged from the notch 459, the implant deployment device can bemanually moved to a position in which the suture tab assembly 450 can bereset such that the latch 458 is reengaged with the notch 459. From thisreset position, proper deployment of an implant can then be attempted.

In several of the embodiments disclosed herein, the handle and cartridgesystem is designed to function properly and deliver an implant when theneedle travels a desired distance beyond the distal portion of thedistal end of the cartridge elongate assembly. Similarly, the handle andcartridge system is designed to function properly and deliver an implantwhen the needle and implant maintain desired relative positions during astep in the implant process. The force limiting springs and forcelimiting connectors disclosed herein assist in preventing damage toelements within the cartridge and handle system when the system is notfunctioning in a way that it can successfully deliver an implant.

According to certain aspects of embodiments disclosed herein, the handleand cartridge system include position indicators that alert a user tocertain conditions in which the handle and cartridge system may beunable to successfully deliver an implant. FIG. 7 illustrates anisometric view of a handle and cartridge system similar to thoseillustrated in FIG. 1 and FIG. 2A. A cartridge 800 is shown as insertedand engaged with a handle 700. A left handle case 702 includes a frontopening in which a needle sled button 745 travels. The needle sledbutton 745 is coupled to a needle sled within the handle 700 (such asthe needle sled 140 illustrated in FIG. 1 ). The needle sled button 745is configured such that when the needle sled 140 is in a proximalposition and the needle of the cartridge is undeployed, a user cantactilely identify that there is a front opening in the left handle case702. When the needle sled 140 moves fully forward and deploys the needleto its full extent of deployment out of the distal end portion of thecartridge elongate assembly, the needle sled button 745 moves forwardwithin the front opening in the left handle case 702 such that theneedle sled button 745 is flush with the front surface of the lefthandle case 702. In this configuration, a user can tactilely identifythat the front opening in the left handle case 702 is completely filledby the needle sled button 745.

In a case where the needle does not completely deploy to its full extentof deployment out of the distal end portion of the cartridge elongateassembly, the needle sled button 745 will not completely fill the frontopening in the left handle case 702. In this case, as user can tactilelyidentify that there has been incomplete deployment of the needle and theuser can take steps to reset the device and attempt deployment again.Thus, the needle sled button 745 provides another mechanism to reduce orprevent damage to the needle, the implant, the suture, or to othermechanisms within the handle and cartridge system.

In another embodiment, the needle sled includes a mechanism thatvisually or audibly alerts a user that the needle has not completelydeployed or that the needle has completely deployed. For example,referring again to FIG. 8 , the cover plate 830 (similar to the coverplate 130 of FIG. 1 ) is modified to include a mounting post for asemi-spherical bell 834. The cover plate 830 also includes a feature tomount a bell spring 832. The bell spring 832 sticks up into the interiorof the bell 834 (this configuration saves space as compared to a bellstriker mounted externally to the bell). The needle sled 840 is modifiedto include an alert arm 836 that contacts the bell spring 832 as theneedle sled 840 moves distally during a needle deployment step asdescribed elsewhere herein. The alert arm 836 causes the bell spring 832to bend over as the alert arm passes underneath the bell 834. That is,the alert arm 836 folds the bell spring 832 over as the alert arm 836moves distally. The alert arm 836 is configured such that is releasesthe bell spring 832 when the needle sled 840 has moved distally to aposition that corresponds with complete deployment of the needle. Thereleased bell spring 832 pops up and strikes the bell 834, indicating tothe user that the needle is completely deployed. Thus, if the user doesnot hear the bell, the user can take steps to reset the system andredeploy the needle. To prevent the bell 834 from ringing again when theneedle sled 840 is repositioned to the initial position and the end of adeployment sequence, the alert arm 836 includes a ramp feature thattemporarily moves the bell spring 832 to the side instead of folding thebell spring 832. Moving the bell spring 832 to the side allows the bellspring 832 to return to its original position without ringing the bell834. One advantage of this design is that it is not sensitive to thespeed of the needle sled. Because the force used to strike the bell isthat generated by the folded spring, a slow moving sled or a fast movingsled will generate the same amount of audible signal.

The embodiments disclosed herein contain aspects that indicate thecomplete deployment of a needle and/or the incomplete deployment of aneedle. There are aspects of embodiments that prevent damage to a needleassembly or to a suture assembly and allow for a manual reset. There areaspects of embodiments that prevent damage to a needle assembly or to asuture assembly and assist in resetting the device. Each of theseaspects may be used in combination with each other where their use iscompatible. For example, there may be an embodiment that includes adeployment indicator and also includes a force limiting feature. Thatforce limiting feature may allow for manual resetting, automaticresetting, or both. The separate description of embodiments is notintended to preclude their use in combination.

Other treatment devices may benefit from the use of the embodimentsdisclosed herein. Treatment devices equipped with various tools whichmanipulate, ablate, or otherwise alter tissue, where those tools aremoved, deployed, or driven by mechanical energy, can benefit from theuse of the force limiting springs and connectors disclosed herein, aswell as the use of the deployment indicators disclosed herein. Suchtools can include, but are not limited to, needles, cutting blades,vacuums, grasping arm assemblies, expandable cutting members, bluntdissectors, noose or ligature clips, articulating heads with an integralor retractable blade, helical blades, electrodes for delivery ofradiofrequency energy, cutting wires or rings, electrocauterizingprobes, or staple or suture delivery heads.

In some embodiments, a treatment device can include an introducer with alumen carrying the tool, and a handle assembly coupled to theintroducer. The treatment device includes a pusher, sled, or deliverymechanism that moves the tool forward thereby unsheathing the tool fromthe distal end of the introducer. This can be done by an actuator ortrigger of the handle assembly.

In certain embodiments, a treatment device can be an apparatus thatdeploys one or more implants to retract, lift, compress, support,remodel, or reposition tissue within a patient’s body. The treatmentdevice can deliver a first or distal anchor component at a firstlocation within a patient’s body and a second or proximal anchorcomponent at a second location within the patient’s body. The treatmentdevice can also impart tension to a connector that attaches the firstand second anchors.

In some embodiments, the treatment device includes a cartridge carryingat least one implant and a handle configured to receive the cartridge.The handle includes an actuator and at least one spring mechanism loadedwith mechanical energy. The handle also includes a member that mateswith the cartridge to transfer mechanical energy from the springmechanism to the cartridge for deploying the implant. The handle andcartridge system includes a first firing sled that has slots aligningwith pusher tabs on a needle assembly. The slots of the first firingsled and the pusher tabs of the needle assembly are complementarymechanisms that allow for the transfer of energy from the springmechanism via the first firing sled to fire a needle in the cartridge.The handle and cartridge system can also include a second firing sledwith slots aligning with pusher tabs on a suture tube or connector tube.The slots of the second firing sled and the pusher tabs of the suturetube are complementary mechanisms that allow for the transfer of energyfrom the spring mechanism via the second firing sled to advance thesuture tube simultaneously with the needle tube.

Other treatment devices may also use movable parts employing mechanicalenergy to introduce tools to an interventional site. If the tools strikebone, calcifications, or other solid or hard anatomical structures, itcan cause damage to the tools and/or the movable parts within thetreatment device. In some cases, although there may not be damage to thetool or the movable parts, the deployment of the tool will beunsuccessful if the tool strike such non-target tissue.

An apparatus for preventing, or at least reducing, deployment failure ofa needle, penetrating member, or other tool due to bone strikes (orstriking other non-target tissue) can include an adjustable,compressible, extendable, or resettable element coupled to the movableparts in a treatment device. In some embodiments, such as when atreatment device includes a connector or tensioning element, theapparatus can prevent, or at least reduce, buckling of the connector dueto bone strikes.

While particular elements, embodiments and applications of the presentinvention have been shown and described, it will be understood that theinvention is not limited thereto since modifications can be made bythose skilled in the art without departing from the scope of the presentdisclosure, particularly in light of the foregoing teachings.

We claim:
 1. An apparatus for manipulating tissue within a subject totreat a medical condition, the apparatus comprising: a first movableassembly coupled to a needle; a second movable assembly coupled to asuturing component, wherein the first movable assembly and the secondmovable assembly are configured to move relative to each other; and aforce limiting element coupled to the second movable assembly and aproximal portion of the suturing component, wherein the force limitingelement is configured to maintain a position of the second movableassembly relative to the first movable assembly.
 2. The apparatus ofclaim 1, wherein the suturing component comprises an elongate tubularmember defining an inner lumen configured to accommodate a suture. 3.The apparatus of claim 1, wherein the first movable assembly isconfigured to move proximally relative to the second movable assembly.4. The apparatus of claim 1, wherein the force limiting elementcomprises a spring.
 5. The apparatus of claim 4, wherein a portion ofthe suturing component is configured to extend through a lumen definedby coils of the spring.
 6. The apparatus of claim 4, wherein the springis a tension spring configured to extend in response to an increase infrictional force received at a distal end of the needle.
 7. Theapparatus of claim 1, wherein the force limiting element comprises alatch configured to reversibly couple with a complementary notch definedby the second movable assembly.
 8. The apparatus of claim 7, wherein thelatch is configured to disengage from the notch in response to anincrease in frictional force received at a distal end of the needle. 9.The apparatus of claim 1, wherein manipulating comprises retracting,lifting, compressing, displacing, approximating, supporting, remodeling,repositioning, ablating, or altering at least a portion of the tissue.10. The apparatus of claim 1, wherein the tissue comprises a prostategland.
 11. The apparatus of claim 1, further comprising an implantconfigured for deployment within the tissue.
 12. The apparatus of claim11, wherein the implant comprises one or more anchor members connectedto a tensioning element.
 13. The apparatus of claim 1, wherein a portionof the suturing component extends through a passage defined by thesecond movable assembly.
 14. The apparatus of claim 13, furthercomprising a friction element configured to conditionally prevent thesuturing component from moving proximally through the passage.
 15. Theapparatus of claim 14, wherein a cross section of the suturing componentis greatest at the friction element.
 16. A cartridge for delivering animplant, comprising: a housing; a movable assembly positioned within thehousing and coupled to a suturing component, wherein the movableassembly is configured to move relative to the housing; and a forcelimiting element coupled to the movable assembly and a proximal portionof the suturing component, the force limiting element configured toabsorb frictional forces received at a distal portion of the suturingcomponent during delivery of the implant to a tissue.
 17. The cartridgeof claim 16, wherein the suturing component comprises a suture and anelongate tubular member defining an inner lumen configured toaccommodate the suture.
 18. The cartridge of claim 16, wherein the forcelimiting element comprises a latch configured to reversibly couple witha complementary notch defined by the movable assembly.
 19. The cartridgeof claim 16, wherein the force limiting element comprises a spring. 20.The cartridge of claim 16, further comprising a needle and an elongateassembly, wherein the needle is configured to slide longitudinallythrough the elongate assembly during delivery of the implant.